<!DOCTYPE html>
<html>

<head>
    <meta charset="utf-8" />
    <title></title>
    <script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
    <script> 
    $(document).ready(function(){
        $("#p1").mouseenter(function(){
            $('#p2').html('您的鼠标移到了 ID =“P1”的元素上！');
        });
    });
        $('#p1').mouseleave(function(){
            ("再见，您鼠标离开了该段落。")
        })
    </script>
</head>

<body>
<p id="p1">鼠标指针进入此处，会看到弹窗</p><br>
<p id="p2"></p>
</body>

</html>